4-methylsulfonyl-2, 6-dinitro-n, n-substituted anilines as herbicides



United States Patent 3,321,292 4-METHYLSULFONYL-2,6-D1NITRO-N,N-SUBSTI- TUTED ANILINES AS EERBICIDES Samuel B. Soloway, Sittingboume, England, and Kenneth D. Zwahien, Modesto, Califi, assignors to Shell Oil Company, New York, N.Y., a corporation of Delawere No Drawing. Filed Oct. 8, 1965, Ser. No. 494,268 13 Claims. (Cl. 712.3)

This invention is a continuationin-part of Serial No. 411,120, filed NOV. 13, 1964 now US. Patent No. 3,227,734.

This invention relates to a method useful in destroying and/ or preventing growth of unwanted plants and to herbicidal compositions. In particular, this invention relates to the use and compositions containing novel 4-(methylsulfonyl)-2,6-dinitro-N,N-substituted anilines found to be very active herbicides.

The herbicidal compounds used according to the invention are represented by the generic formula:

O l u wherein R and R" each is alkyl or alkenyl of at least two carbon atoms but together contain a total of no more than eight carbon atoms; R and R" together may form an alkylene radical of up to 8 carbon atoms.

Such alkyl substituents as ethyl, isopropyl, n-propyl, n-butyl are suitable while suitable alkenyl groups include vinyl, allyl, methallyl or butenyl. The alkyl or alkenyl substituents may be straightor branched-chain.

R and R may be the same or they may be difierent. Both may be alkyl or alkenyl or R may be alkyl while R" is alkenyl.

Exemplary of such herbicidal nitroanilines used according to the invention are:

4-(methylsulfonyl)-2,6-dinitro-N,N-diethylaniline 4- (methylsulfonyl) -2,6-dinitro-N,N dipropylaniline 4-(methylsulfonyl)-2,6-dinitro-N,N-dibutylaniline 4-(methy1sulfonyl)-2,6-dinitro- -ethyl, N-propylaniline 4-(methylsulfonyl)-2,6-dinitro-N-ethyl, N-butylaniline 4-(rnethylsulfonyl)-2,6-dinitro-N-propyl, N-butylaniline 4-(methylsulfonyl)-2,6-dinitro-N-viny1, N-ethylaniline 4-(methylsulfonyl)-2,6-dinitro-N-viny1, N-propylaniline 4- (methylsulfonyl)-2,6-dinitro-N,N-diallylauiline 4-(methylsulfonyl -2,6-dinitro-N-allyl, N-ethylaniline 4-(methylsulfonyl)-2,6-dinitro-N-allyl, N-propylaniline 4-(methylsulfonyl)-2,6-dinitro-N-allyl, N-butylaniline 4- (methylsulfonyl) -2, 6-dinitro-N,N-di Z-methallyl) aniline 4- methylsnlfonyl) -2,6-dinitro-N- (Z-methally) N-ethylaniline 4-( methylsulfonyl -2,6-dinitro-N- (2-meth allyl) N-propylaniline 4-(methylsulfonyl)-2,6-dinitro-N-butenyl, N-allylaniline 4-(methylsulfonyl)-2,6-dinitro-N-butenyl, N-propylaniline l- [4- (methylsulfonyl) -2,6-dinitrophenyl] hexahydrolH-azepine 1- [4- (methylsulfonyl) -2,6-dinitrophenyl] octahydro lH-azocine Preferred because of their especially eflective herbi cidal properties and their ability to control weeds at relatively low dosages are those nitroanilines wherein R and R" are independently alkyl or alkenyl of at least two carbon atoms and R and R" together contain from t0 7 carbon atoms. It has been found that when R or R", for example, is represented by hydrogen or methyl, the resulting 4-(methylsulfonyl)-2,6-dinitroanilines are rela- 3,321,292 Patented May 23, 1967 No. of C atoms, Lbs. per acre for R'+R" control Tests on other plant species have confirmed this finding. The nitroanilines of this preferred class are effective herbicides against a wide range of economically important weeds.

Examples of such preferred herbicides are:

4-(methylsulfonyl)-2,6-dinitro-N-ethyl, N-propylaniline 4-(methylsulfonyl)-2,6-dinitro-N-ethyl, N-butylaniline 4-(methylsulfonyl -2,6-dinitro-N,N-dipropylaniline 4-(methylsulfonyl)-2,6-dinitro-N-propyl, N-butylaniline 4-(methylsulfonyl)-2,6-dinitro-N-ethyl, N-allylaniline 4-(methylsulfonyl)-2,6-dinitro-N-propyl, N-allylaniline 4- (methylsulfonyl -2,6-dinitro-N,N-diallylaniline The following examples are presented to show how typical compounds used according to the invention can be prepared and to illustrate the effectiveness of typical members as herbicides.

In the following examples, the parts given are by weight.

Example I .Preparation of 4-(methylsulfo'nyl)-2,6- dinitro-N,N-dipropylaniline A. Preparation of 4-chZora-3,5-ziinizrophenyl methylsz llfone.-6 parts of 4-chloro-3-nitrophenyl methylsultone was added portionwise to a mixture of 49 parts of turning H 50 (30%) and 16 parts of red fuming HNO (d. 1.60) at 30 C. The reaction was heated with stirring to 140 C. for 3 hours, then poured over ice. The separated solid was filtered, water-washed, and dried. The product was recrystallized from dimethyl formamide solution by adding alcohol to give 4.5 parts of pale yellow crystals, M.P. 201-203 C. Structure confirmed by elemental analysisviz. (percent by weight).

Calculated for N SO ClC H Cl, 13.7; N, 10.0. Found: Cl, 12.9;N, 10.0.

B. Preparation of 4-(methylsulfonyl)-2,6-dinitr0-N,N- dipr0pylaniline.l5 parts of 4-chloro-3,S-dinitrophenyl methylsulfone was suspended in 120 parts of methanol and 15 parts of dipropylamine were added. The reaction mixture was heated for two hours, chilled, and the separated solid filtered. The produnct was Washed and recrystallized to give 18 parts of golden crystals, M.P. 151 C. (97% yield). Structure confirmed by elemental analysis-viz. (percent by weight).

Calculated for N SO C H N, 12.2; S, 9.3. Found: N, 12.0; S, 9.3.

Example II.-Preparazi0n of 4-methylsulf0nyl-2,6-dinitr0- N,N-diallylaniline 14 parts of 4-chloro- 3,S-dinitrophenyl methyl sulfone was suspended in 120 parts of methanol in a reaction flask equipped with a mechanical stirrer. 10 parts of diallyl amine was added to the mixture dropwise. The reaction mixture was heated to reflux for 1 /2 hours, cooled in an acetone-Dry Ice bath, and solid which formed was filtered. The solid was recrystallized from methanol to give 12 parts of yellow crystals, M.P. l08111 C. (71% yield). Structure confirmed by elemental analysis-viz. (percent by weight).

Calculated for =N SO C H N, 12.3; S, 9.4. Found: N, 11.0; S, 9.1.

In a similar manner other dinitroanilines according to the invention were prepared by reacting the appropriate amine with 4-chloro-3,5-dinitrophenyl met-hylsulfone in a manner similar to that of Example I;

Example III TABLE I.PRE-EMERGENCE SOIL HERBICIDE TESTS 10 1bs./A Watergrass 10 lbs/A Test Compound Cress 4- (methylsulfonyl)-2,6-dinitro-N,N-diethyla ne 4- (methylsulfonyl)-2 nitr-N,N-dipropylaniline 4- (methylsulfonyl)-2,6-dinitr0-N ,N-dibu tylaniline 4-(methylsulfonyl)-2,6'dinitro-N-propy1, N

butylaniline 4- (mcthylsult'onyl) -2,6-dinitro-N- butylaniline 4- (methylsulfonyl) -2,6-dinitr propylam'line 4-(methylsulfonyl)-2,6-diuitro-N,N-dial1ylaniline ethylaniline -(methylsulfonyl 2,6

methallyl) aniline. 1-[4-(methylsulfonyl)-2,6-dinitr0pl1enyl]hexahydro-lH-azepine Ht (methylsulfonyl) -2,6-dim'trophenyl]oct0- hydro-lH-azocine moowocoooooow Example IV The post-emergence herbicide activity of the compounds used according to the invention was evaluated by spraying dilute suspensions of the compounds in a 1:1 mixture of acetone and water with 0.5% wetting agent on crabgrass (Digitarz'a sanguinalis) and pigweed plants (Amaranthus sp.) grown under controlled conditions. After the plants were held for 1 0 to 11 days, they were rated for treatment effect on a 0 (no effect) to 9 (total plant kill) scale. The results are set forth in Table II.

TABLE II.POST-EMERGENCE SPRAY HERBICIDE TESTS Weed control rating Test Compound 10 lbs/A Orabgrass 10 lbs/A Pigweed 4-(methylsulfonyl)-2,6dinitro-N,N-diethylaniline 4-(methylsulf'onyl) -2,6-dinitro-N,N-dipropylaniline 4-(methylsulionyl 2,6

aniline 4(methylsulfonyl)-2,6-dinitro-N-pr0pyl, N-

butylaniline 4-(methylsulfonyl)-2,6dinitro-N-ethyl, N

propylaniline 4 (methylsulfonyl) 2 fi-dinitro-N N-diallylaniline 4(methylsulfonyl)-2,6 initro-N-ethyl, N-

allylaniline 4-(methylsulfonyD-2,6-dinitro-N-propy1, N-

allylaniline Example V.-Field tests The pre-emergent and post-emergent activity of 4- (methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline has been evaluated in field tests. When a logarithmic series of dosages of this compound was sprayed onto bare soil, it was found that control of ryegrass was obtained at 0.8 pound per acre while less than 0.2 pound per acre controlled crabgrass. This nitroaniline is therefore a highly effective pre-emergent herbicide.

:In further pre-emergence tests watergrass and pigweed plants were controlled with 4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline in the field at a series of logarithmic dosages and it was found that 95% control of watergrass was obtained at the dosage of 0.3 pound per acre while 1.6 pounds per acre controlled 95% of the pigweed. 4-(methylsulfonyl)-2,6-dinitro N,N-dipropylaniline is also a very promising post-emergent herbicide.

In a similar pre-emergent tests, 4(methylsulfonyl)-2,6- dinitro-N,N-diallylaniline controlled 95% of ryegrass at 2.7 pounds per acre, cheatgrass at 6.1 pounds per acre, dock and pigweed at less than 1 pound per acre.

Also active as pre-emergent herbicides in advanced tests were 4-(methylsulfonyl)-2,6-dinitro-N-propyl, N- butylaniline; 4-(methylsulfonyl)-2,6-dinitro-N-ethyl, N- butylaniline; 4-(methylsulfonyl)-2,6-dinitro-N-ethyl, N- propylaniline and 4-(methylsulfonyl)-2,6-dinitro, N- propyl, N-allylaniline.

One advantage of the nitroaniline herbicides of this invention is that they are not very volatile, and tend to remain in that part of the soil into which they are introduced; some may be moved through the soil by water. Consequently, by appropriate selection of the part of the soil into which they are introduced, relative to the seeds of wanted plants and those of unwanted plants, and taking into account the effect of water, these herbicides can be used to prevent all plant growth, even at relatively low dosages in some cases, or their selectivity can be improved to prevent growth of unwanted plants without harm to wanted plants. For example, as is well known, only those weed seeds which are present within about one-quarter inch of the surface of the soil will germinate, whereas the seeds of cereal, and other, crops, for example, ordinarily are sown about one-half to three-quarters of an inch below the surface of the soil, and germinate Well under those conditions. By introducing the herbicide only into the top one-quarter inch of the soil, and avoiding excessive watering, germination of the weed seeds can be prevented, while germination of the crop weeds will not be effected. Thus, even those herbicides of this invention that are not very selective in their action can be used to selectively remove the weeds from cereal grains or other crops. Of course, if complete kill of all plants in a given portion of soil is desired, it is necessary only to introduce one or more of the nitroanilines herbicides throughout that portion of soil.

The nitroanilines are soluble in the common organic horticultural solvents. Thus, according to the intended method of application, the character of the plants involved, and the concentration of herbicide to be used, the herbicidal nitroanilines can be formulated as a solution or suspension in water, or a suitable nonphytotoxic organic solvent, as a dispersion or emulsion of the active agent in a non-solvent therefor, as an emulsion of a solution of the active agent in a suitable solvent emulsified with a second, inhomogeneous liquid, or as a solid comprising the active agent or agents sorbed on a sorptive solid carrier.

When a light hydrocarbon oil is to be used as carrier, suitable materials for the purpose include any of the spray oils marketed commercially for this purpose. The highly aromatic hydrocarbons are preferred. Thus, highly refined aromatic hydrocarbons, such as benzene, toluene, xylene, ethylbenzene, cumene or isodurene, may be used, or the carrier may be a less highly refined relatively aromatic hydrocarbon mixture, such as a coal tar fraction, a straight-run petroleum distillate, a thermally or catalytically cracked hydrocarbon oil, platformate, or the like. Suitable solvents may also comprise a relatively aliphatic hydrocarbon material, or mixtures of aromatic and aliphatic hydrocarbons. Suitable aliphatic hydrocarbon ma terials include refined gas oil, light lubricating oil fractions, refined derosene, mineral seal oil and the like. Spray oils boiling in the range of from 275 F. to 575 F. are suitable, as are spray oils boiling in the range of from 575 to 1000 F. and having an unsulfonatable residue of at least 75 Mixtures of such spray oils also may be used.

Although the solvent usually will be of mineral origin, animal or vegetable oils as well as synthetic solvents also may be employed in or as the carrier. In appropriate cases oxygenated solvents, such as alcohols, e.g., methanol, ethanol, isopropyl alcohol, n-butyl alcohol and amyl alcohol, ketones, e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone, etc., glycols and glycol ethers and chlorinated solvents may be employed in or as the carrier.

Solutions of the active agents may be applied as such to the plants or to the soil that is to be treated, or they may be suspended in water and the suspension or emulsion applied to the plants or soil. Thus, a relatively concentrated solution of the active agent in a water-immiscible solvent may be prepared, with added emulsifying, dispersing or other surface-active agents, and the concentrate diluted in the spray tank with water to form a uniform fine emulsion which can be applied by conventional spray devices. Emulsions or dispersions of the active agents as such in water may also be prepared and applied.

Suitable emulsifiable concentrates, adapted for dispersion in water to provide a sprayable composition, ordinarily will contain between about by Weight and about 50% by weight of active agent dissolved in a hydrocarbon or other suitable water-immiscible solvent. Minor amounts, for example, about 0.5% by weight to about by weight, of emulsifying agents may be included to promote dispersion of the concentrate in Water. Suitable emulsifying agents include, among others, alkaryl sulfonates, sulfates of long-chain fatty acids, alkylaryl polyoxyethylene glycol ethers, sulfonated white oils, sorbitan esters of long-chain fatty acids, alkylamide sulfonates and the like. Although both anionand cation-active wetting and emulsifying agents may be used for this purpose, the non-ionic agents are preferred since the concentrates in which they are present have increased stability and do not suffer phase separation when diluted with hard water. Suitable non-ionic agents which may be used are available commercially as, for example, Triton X-100 and Lissapol Nbelieved to be condensation products of alkylphenols with ethylene oxide-and Tweens-believed to be condensation products of ethylene oxide and higher fatty acids esters, for example, oleic acid ester of anhydrosorbitols.

Liquid compositions of these herbicidal nitroanilines suitable for application to plants or to their environment contain the active agent or agents in concentrations generally within the range of from about 0.01% by Weight to about 50% by weight.

The invention includes novel solid compositions of matter wherein the active agent or agents are absorbed or absorbed in or on a sorptive carrier, such as finely divided clay, talc, gypsum, lime, wood flour, fullers earth, kieselguhr, or the like. The solid composition, or dust, may contain from as little as 1% by weight of active material to 75% by weight of active material, or even more. It may be prepared as a dust, or as granules designed to be broadcast or to be worked into the soil. Compositions formulated as wettable powders are particularly suitable. Wettable powders can be prepared suitable for suspension in water with or without the aid of conventional dispersing or deflocculating agents and with or without such adjuvants as oils, stickers, wetting agents, etc.

For field application, the rate of application of the active agent may be varied from about 0.1 to 30 or more pounds per acre. It will be appreciated that the rate of application is subject to variation according to the particular active agent used, the particular species of plants involved, and the local conditions, for example, temperature, humidity, moisture content of the soil, nature of the soil, and the like. Efiective resolution of these factors is well within the skill of those well versed in the herbicide art.

The herbicidal compositions may contain one or more of the herbicidal nitroanilines set out hereinbefore as the sole active agent, or they may contain in addition thereto other biologically active substances. Thus, insecticides, e.g., DDT, endrin, dieldrin, aldrin, chlordane, demeton, methoxychlor, DDVP, naled, methylbenzyl B-hydroxycrotonate dimethyl phosphate, rotenone and pyrethrum, and fungicides, such as copper compounds, ferbam, captan, and the like, may be incorporated in the compositions. Further, if desired, the herbicidal compositions may contain fertilizers, trace metals, or the like and when applied directly to the soil may additionally contain nematocides, soil conditioners other plant regulators, such as naphthalene acetic acid, 2.4-dichlorophenoxyacetic acid and the like, and/or herbicides of difierent properties.

We claim as our invention:

1. A herbicidal composition comprising from about 1 percent to about 75 percent by weight of the total composition of a compound of the formula:

wherein R and R each is a member of the group consisting of alkenyl of at least two carbon atoms and alkyl of at least two carbon atoms, R and R" together containing a total of no more than eight carbon atoms, and with the proviso that R and R" together can represent unsubstituted alkylene of six to seven carbon atoms, and an inert horticultural diluent therefor.

2. A herbicidal composition according to claim 1 wherein R and R each is a member of the group consisting of alkenyl of at least two carbon atoms and alkyl of at least two carbon atoms, R and R together containing a total of from five to seven carbon atoms.

3. A herbicidal composition according to claim 1 wherein the active ingredient is 4-(methylsulfonyl)-2,6- dinitro-N,N-dipropylaniline.

4. A herbicidal composition wherein the active ingredient is dinitro-N,N-diallylaniline.

5. A herbicidal composition wherein the active ingredient is dinitro-N-propyl, N-butylaniline.

6. A herbicidal composition wherein the active ingredient is dinitro-N-ethyl, N-butylaniline.

7. A herbicidal composition wherein the active ingredient is dinitro-N-ethyl, N-propylaniline.

8. A method of controlling unwanted plant growth which comprises bringing into contact with said plants a herbicidally effective amount of a compound of the formula:

according to claim 1 4- (methylsulfonyl) -2,6-

according to claim 1 4- (methylsulfonyl) -2,6-

according to claim 1 4- (methylsulfonyl) -2,6-

according to claim 1 4- (methylsulfonyl -2,6-

wherein R and R" each is a member of the group consisting of alkenyl of at least two carbon atoms and alkyl of at least two carbon atoms, R and R" containing a total of no more than eight carbon atoms, and with 7 8 the proviso that R and R" together can represent 13. A method of controlling unwanted plant growth unsubstituted alkylene of from six to seven carbon according to claim 8 with 4-(methylsulfonyl)-2,6-dinitroatoms. N-ethyl, N-propylaniline. 9. A method of controlling unwanted plant growth according to claim 8 with 4-(methylsulfonyl)-2,6-dinitro- 5 References Cited y the Examiner ,i gg pyig g t H t d 1 t th UNITED STATES PATENTS me' 0 0 con r0 mg unwane pan grow according to claim 8 with 4-(methylsulfonyl)-2,6-dinitr0- 5P 71 2'3 meman 712.3 NNmanylamlme' 3 257 190 6/1966 So 6r 71- 2 3 11. A method of controlling unwanted plant growth 10 p according to claim 8 with 4-(methylsulfonyl)-2,6-dinitro- FOREIGN PATENTS N-pmPylN-butylaniline- 666,837 7/1963 Canada.

12. A method of controlling unwanted plant growth according to claim 8 with 4-(methylsulfonyl)-2,6-dinitro LEWIS GOTTS Pnmary Examme' N-ethyl, N-butylani'line. 15 JAMES O. THOMAS, ]R., Examiner. 

1. A HERBICIDAL COMPOSITION COMPRISING FROM ABOUT 1 PERCENT TO ABOUT 75 PERCENT BY WEIGHT OF THE TOTAL COMPOSITION OF A COMPOUND OF THE FORMULA 